The Age, Formation and Evolution of the Elements

俄克拉荷马大学诺曼校区的约翰·J·考恩博士将继续他对重元素的形成、年龄和演化的研究，特别是那些在银河系最古老的恒星中缓慢和快速的中子捕获过程中形成的重元素。考恩博士和他的合作者在几颗银河系晕星中发现了长寿命的放射性元素钍，最近又在一颗晕星中发现了铀，这可能为直接确定最古老恒星的年龄提供了一个独特的机会。考恩博士还将介绍一对计时器Th/Hf，用于测定银河系中最古老恒星的年龄。这些独立于宇宙学模型、参数和化学演化模型的研究，将比以前更准确地估算出最古老恒星的年龄，并有助于回答银河系和宇宙年龄的基本问题。拟议的研究活动的更广泛影响涉及几个领域。这项由美国国家科学基金会支持的研究直接纳入了考恩博士为非理科生开设的定期天文学入门课程的课程设置。研究生和本科生都参与到考恩博士的研究活动中，包括接受考恩博士培训和指导的女学生。作为公众宣传的一部分，考恩博士还定期向公众发表关于天文学的公开讲座。

Dr. John J Cowan of the University of Oklahoma-Norman Campus, will continue his research on the formation, age and evolution of the heavy elements - specifically those formed in the slow and rapid neutron-capture processes in the oldest stars in our Galaxy. The detection by Dr. Cowan and his collaborators of the long-lived radioactive element thorium in several, and recently uranium in one, Galactic halo stars has provided a perhaps unique opportunity to directly determine the ages of the oldest stars. Dr. Cowan will also introduce a chronometer pair, Th/Hf, to make age determinations for the oldest stars in the Galaxy. These studies, independent of cosmological models and parameters and chemical evolution models, will result in more accurate age estimates for the oldest stars than previously possible and will help to answer the fundamental questions of just how old are the Galaxy and the Universe.The broader impacts of the proposed research activity involve several areas. The NSF-supported research is incorporated directly into the course curriculum of Dr. Cowan's regularly taught introductory astronomy course for non-science majors. Both graduate and undergraduate students are involved in the research activities of Dr. Cowan, including female students who are being trained and mentored by Dr, Cowan. As part of public outreach, Dr. Cowan also regularly gives public lectures on astronomy to the general public.